Which two statements about subqueries are true?

Which two statements about subqueries are true? (Choose two.)

A.
A subquery can retrieve zero or more rows.

B.
Subqueries CANNOT be nested by more than two levels.

C.
A subquery CANNOT be used in an SQL query statement that uses group functions.

D.
When a subquery is used with an inequality comparison operator in the outer SQL statement,
the column list in the SELECT clause of the subquery should contain only one column.

E.
A subquery can be used only in SQL query statements.

F.
A subquery should retrieve only one row.

Explanation:

: subquery can retrieve zero or more rows, subquery is used with an inequality camparison
operator in the outer SQL statement, the column list in the SELECT clause of the subquery should
contain only one column.
Incorrect answer :
* subquery can retrieve zero or more rows
* subquery is not SQL query statement
* subquery can be nested
* group function can be use with subquery